Zaymiey

🔬 Biology  ·  Organisms and Populations  ·  NEET

If the per capita birth rate equals the per capita death rate in a population, the value of r is zero, which means the population will:

Answer: Remain stable in size.

  • A Grow exponentially
  • B Remain stable in size
  • C Decline rapidly to extinction
  • D Exceed its carrying capacity

Correct answer: B. Remain stable in size

Explanation: When births balance deaths, r equals zero and dN/dt is zero, so population size stays essentially constant over time.

Exponential (J-curve) vs Logistic (S-curve) GrowthtimePopulation (N)Exponential (unlimited resources)K (carrying capacity)Logistic (limited resources)Logistic growth slows as N approaches K; exponential growth never slows down

Exponential growth produces an ever-steepening J-curve with no limit, an unrealistic long-term model; logistic growth produces an S-curve that levels off at the carrying capacity K, as growth rate (K−N)/K shrinks to zero once resources are fully used.

Concept context

How organisms interact with abiotic factors and respond to stress, plus population attributes, growth models, and interspecific interactions such as predation, competition, and mutualism.

Read the full Organisms and Populations notes →